What about torquing the bow with the bow hand? Could that also contribute to shooting to the right?
I just started shooting a recurve with more of a pistol-like grip about a month or two ago. Before then, I had been shooting a long bow for about a year and a half. I immediately noticed my shots were going to the right, and the further the distance from the target, the more to the right they were. At about 10 yds, I had groups in the center, but at 20, they were way too the right, about 6" to 10" or so. I had been gripping the bow lightly, but with more of an up-and-down, vertical type fist like I would normally grip my longbow.
Tonight, I tried for the first time a grip with more of a 45-degree angle, almost like a normal fist when a punch almost reaches its full extension, but not quite horizontal. I immediately noticed a drastic improvement - no more shots to the right. Of course, it could be that I fixed something else, like my release, without realizing it, but it's too coincidental. I'll continue to try the 45-degree angle grip to see if that fixed it for good. I only thought I'd mention the grip and the possibility that it might be torquing the bow? Hope this helps.